let obj={
    a:123,
    //[1,2,3]:123
}
console.log(obj);

let map1=new Map();
map1.set('a',123);
map1.set(['a','b'],123);
map1.set(0,'你好');
console.log(map1);
console.log(map1.size);
console.log(map1.get('a'));
console.log(map1.get(0));
console.log(map1.delete(0));
console.log(map1.size);
console.log(map1.clear());
console.log(map1.size);